SAN FRANCISCO— Today the Center for Biological Diversity petitioned the state of California to regulate carbon dioxide pollution under the federal Clean Water Act. The petition marks the first step towards regulating carbon dioxide emissions from power plants, cement kilns, oil refineries, and other industrial sources due to the adverse effects of carbon dioxide pollution on the ocean.

Carbon dioxide is the most prevalent greenhouse gas, and not only contributes to global warming but also causes ocean acidification. The ocean absorbs CO2, which reacts with seawater to make it more acidic—thus altering the chemical composition of the ocean. Approximately half of the carbon dioxide emitted into the atmosphere from fossil fuel burning and cement production over the past 200 years has been absorbed by the oceans.

Carbon dioxide pollution has already lowered average ocean pH by 0.11 units, with a pH change of 0.5 units projected by the end of the century under current emission trajectories. These changes are likely to have devastating impacts on the entire ocean ecosystem.

The primary known impact of acidification is impairment of calcification, the process whereby animals such as corals, crabs, abalone, oysters, and sea urchins make shells and skeletons. Many species of phytoplankton and zooplankton, which form the basis of the marine food web, are also particularly vulnerable to ocean acidification. Laboratory studies have shown that at carbon dioxide concentrations likely to occur in the ocean in the next few decades, the shells of many marine species dissolve, killing the organisms. Absent significant reductions in carbon dioxide emissions, ocean acidification will accelerate, likely ultimately leading to the collapse of oceanic food webs and catastrophic impacts on the global environment.

“Ocean acidification is as grave a threat to the health of our planet as global warming,” said Miyoko Sakashita, a staff attorney with the Center for Biological Diversity who specializes in ocean issues. “Fortunately, the Clean Water Act provides the tools to regulate carbon dioxide pollution, which will help address not only ocean acidification but also global warming.”

While the Environmental Protection Agency under the Bush administration has taken the position that carbon dioxide cannot be regulated as a “pollutant” under the Clear Air Act, the Environmental Protection Agency already lists pH as a “pollutant” in its Clean Water Act regulations. Because CO2 is absorbed by the ocean, lowering the pH of seawater, carbon dioxide emissions therefore can and must be regulated under the Act.

Today’s petitions, submitted to California’s Regional Water Quality Control Boards, seek the listing of all ocean waters under the jurisdiction of the state as “impaired” due to the lowering of pH from the absorption of carbon dioxide pollution. Under the Clean Water Act, states must create a list of water bodies that are being degraded or not attaining water-quality standards and set limits on the input of pollutants into these bodies of water to prevent further degradation. In this case, the Clean Water Act would require limits on carbon dioxide emissions that contribute to ocean acidification.

“Until Congress passes legislation explicitly aimed at substantially reducing carbon dioxide emissions, the Clean Water Act is very likely the best legal mechanism for curtailing these emissions that are destroying our oceans as well as our atmosphere,” said Sakashita.

The Center for Biological Diversity will shortly be submitting similar petitions to all other states that have jurisdiction under the Clean Water Act over ocean waters. Legal action under the Clean Water Act is also being prepared against some of the nation’s largest carbon dioxide emitters for polluting activities that are contributing to ocean acidification.